_These lesions are extremely infectious_ and the disease may be conveyed by kissing, by the common use of small domestic utensils, by the pipe, by dentists’ instruments, etc. Patches occurring at the junction of the skin and mucous membrane may extend over onto the latter and become deep, specific ulcers. Lesions of this character need judicious local as well as constitutional treatment. They will often disappear under the latter alone, but it should be combined with local measures. These consist in cleanliness and the use of various antiseptic solutions or applications. An antiseptic mouth wash, as diluted hydrogen dioxide, or of water given a mahogany color by tincture of iodine, should be frequently used. There should be an application of a 5 per cent. solution of silver nitrate, or some other astringent, stimulating, or mild caustic. [Illustration: FIG. 24 Grouped papulopustular syphilide and numerous pigmented spots from former lesions. (Fordyce.)] =The Skin.=--The late syphilides of syphilis belong to the _gummatous_ or _tuberculous_ types (_i. e._, tuberculous in the anatomical sense, or nodular). The latter may occupy the entire thickness of the skin or lie even deeper. Such lesions may begin as papules and develop into distinct and circumscribed nodules, while these may coalesce into considerable masses. These tend to break down and leave scars after they have disappeared. There is little difference, microscopically, between the nodule and the gumma. Clinically, the tuberculous lesions spread usually in a serpiginous manner, producing a more or less curvilinear outline. (See Figs. 24 to 27.) These ulcerations undermine the tissues to a greater or less extent, and pus and debris will be formed in consequence. In this way they imitate considerably the lesions of lupus, and it may require a careful study of the case and of its history to make a diagnosis. Some of these lesions are extremely slow in their course and long in duration. When scars form they are usually white and smooth, with irregular borders, but sometimes are surrounded by pigment that makes them characteristic. The extent of the scar is no criterion as to the size of the originating lesion, the former being always smaller than the latter. [Illustration: FIG. 25 Ulcers resulting from deep ecthymatous syphilide. (Fordyce.)]